Uninstalling VB X6 made no difference with the App Store & Mountain Lion. Possibly there could be a need for a restart after the unistall. But I'm in the middle of another attempt at a solution and will have to wait for that.

I'll give the Intego site instructions for more info - possibly there's more and possible suggestions.

As the last few people have stated, disable virus barrier X6 (open virus barrier, go into preferences, advanced, select protection off) then delete the app store var file (use spotlight to find and open console, in console search for "/var/folders", open the error message and locate the line "file://localhost/var/folders/ab/...", now open a finder and on the menu bar click go/go to folder and enter /var/folders then locate your "ab" folder or what ever its called on your machine [its different on everyone's] and move it to the trash. Open the app store and try again.

I did all this without a reboot and Mountain Lion has started to download.

Worries the heck out of me if Virus Barrier works with Mountain Lion, but I'll cross that bridge when I get there.

After uninstalling VirusBarrier, still no success with the App Store. But, after rereading the search for the var folder, and the app store folder, FINALLY after deleting it I can purchase/download Mountain Lion. Very frustrating day. I even erased my boot drive and was reinstalling my "mirror" thinking there was something up with it (drastic move - yes).

Now back to waiting for the download(s) to finish (I'm also redownloading 10.7 to keep on disk).

Thanks so much! I uninstall VirusBarrier and delete com.apple.appstore, restart my comp. Viola! I can download Mountain Lion. I wouldn't thought this would be the case by uninstalling Virus Barrier, it should be any ways conflicting with the downloads, oh well at least it works now =). Thanks!

Thanks for the info. Worked perfectly for me, without uninstalling VirusBarrier, but by following your instructions and turning it off instead (open virus barrier, go into preferences, advanced, select protection off). I also moved the var "com.apple.appstore" folder to trash (it's called "gc" instead of "ab" on my machine). I did not have to reboot. Mountain Lion is downloading now, somewhat slowly. It seemed to be frozen for a few minutes, btw.

I too, am a little concerned about whether or not VirusBarrier will be compatible with Mountain Lion, post upgrade. I'm sure this will be solved sooner rather than later by Apple/Intego.

After Mountain Lion installed, and rebooted, Virus Barrier automatically started back up and is running normally. I am able to run file scans, check for updated virus definitions, etc. Also verified that the firewall is running properly. So far, it's all good.

Disabling Anti-Virus software is usually a reccomended step when installing/upgrading many applications (at least in the PC world). I was a little shocked at how many people seemed to jump directly onto the de-installation option.

yeah I had the same issue, although we have two macbook pro's ( me and my wife both late 2009 running lion), my wife could download mountain lion just fine but I couldn't and got the "product distribution error" instead. Both of us were running virus barrier x6. I disabled the virus barrier, went onto the /var/folder and deleted just the com.apple.appstore file. I then rebooted my machine and I could download mountain lion after that. Just keep in mind that you uncheck the enable virus barrier option on system startup in tha advanced virus barrier section. Hope that helps.

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